Mechanical gearing for transmission of power.



G. IVI. EATON.

MECHANICAL GEARING FoR TRANSMISSION 0F POWER.

APPLICATION FILED 1L|LY2I19I3I Patented Muy I6, 1916.

LISSJIYR.

WITNESSES:

Ji. itin GEORG-E M. EATN, GF WILKNSBURG, PENNSYLVANIA, ASSGNOR T0 TESTINGHUSE ELECTRIC .AND MANUFACTURING COMPANY, A CORPORATION' 0E' PENNSYLVANIA.

Specification of Letters atent.

Patented May liti, lilith Application led J'uly 2, 1913. Serial No. 776,90.

To all whom t may concern Be it known that I, (luenen M. Enron, a citizen ot' the llnited States, and a resident otl 'llfilliinsburog in Vthe county of Alle ghenY and State ot Pennsylvania, have invented a new and useful Improvement in Mei'rhanical Gearing' tor riransinission oit Power, of which the following :is a specifi` cation.

My invention yrelates to mechanical gearinta' 'tor the transmission ot' power and it has special reference to gears. pinions or racks that aref` adapted to transmit large amounts of power.

, The .object ol my invention is to provide a girar, or the like. having' teeth ot a conuation and arrangement adapted to cii'ect a uniform and smooth transn'iission ot' power, and which shall be strong' and durable Vin constrlu'tion. ell'ectiie `in operation and which. it desired, may be readily produc-ed by continuous cutting' strokes across the. full i'ace of the gear.

More specilically, the object ot my invention is to provide a tgear ha ving' overlapped symmetrically disposed teeth which, in development, are either' ot continually varying' curvature, such as parabola, hyperbola, ellipse, epieyeloid, or the like` or ot' a compound curvature. 'In'employing the terni compound curvature I refer to plane curves emnprising various portions having ditl'erent radii ot curvature.

overlapping straightdine teeth, have/been employed and have operated eti'eetirely and satisfactorily, but they are expensive and dillicult to nianut'acture, inasmuch as such gears are usually composed ot two supplemental parts which are eut separately and' ."lereto't'ore, herring-bone gears, haring amounts ot' power for the reason that, it 55 the curratiu'e et the 'teeth made suti` cicntly slight to secure the requisite strength at the ends thereofA- the 'teeth do not overlap suthciently to he of 'vice 1u etlecting' a smooth and uniform transmission oi power, ou

whereas, it the curvature be suitieiently great to permit the desired overlapping' of the teeth, the end portions thereof meet the edge ot' the gear at an angle which produces very thin and weak tips. Such a construotion is undesirable because the wear oi the teeth starts at the outer ends, particularly when the pinion or gear is overhang' he yond its sha 't't bearing.

According to my invention, i propose 'to 70 con'ihine the advaiitageous features oi the herringbone and circular toothed gear and to eliminate. the. interior points of their de-I sign and construction.

I shall. describe my invention as an article ot manufacture and irrespective of Ythe manner in which it may be produced. It should, however, he understood that the teeth may conveniently be cast or preferably eut by means oi a machine which is adapted to move the cutting tool in continuous sweep-V ing stroke of the required our ature across the face of' the'gear.

ln the accompanyine` drawing, Figure l is a View in side elevation of a portion ot a gear constructed in accordance with my invent-ion, and Fig'. Q is a development of a 'portion oi the gear showing the curvature oi' the teeth and their relation to each other.

Referring' to the drawing, a gear body l so of any common form provided with a4 plurality oi correspondingly disposed. conn tinuous teeth 2 which may be either of compound or ot' varying curvature, and are synnnetrical in coniiguration with respecte5.y

to the. median plane of the gear. The 'teeth Qlare preferably of the usual involute type and have their portions 3 of maximum our rature in substantially the median plane of' the gear, the end portions 4; thereoi2 beingI of tot) materially less curvature and meeting the edges of the gear at angles which are sutli cieiitly great to permit of strength and durability. As has already been stated, the particular configuration or curvatui'e of the teeth Q may be either compound, that is, made up of several circular sections of different radii, or of the 4continually varying curvature, such as the parabola, liyperbola, etc. I do not wish to be restricted to any of the forms mentioned, as I intend to cover teeth of configuration which depaits from a single circular arc, straight lines, or a combination of both.

The total curvature of the teeth is such that a line joining the extremities of the end portions 4 of any one tooth cuts one of the adjacent teeth and, furthermore, is subz, stantially tangent to the point of maximum only such curvature of the second adjacent tooth. This particular relationship of parts is not essential, and variations in the total curvature are contemplated.. Moreover, the teeth are preferably so shaped throughout their entii'e length that all sections thereof, cut by planes parallel to the median plane of the geai', are identical.

During one direction of operation of two companion gears, the teeth come into engagement first at their end portions 4r, atteiwhich the point of contact moves inward toward the center portions 3' of maximum curvature. Moreover, before one set of co operating teeth becomes disengaged, the set adjacent thereto makes contact with one another and take up a portion of thc load, so that the transmission of power is continuous and uniform, in the same manner as is obtained with herring-bone gears.

My proposed geais, therefore, are adapted to, transmit power smoothly throughout the entire length of 'the teeth and Without end thrust, and, at tlie same time, the curvature thereof is such that the requisite strength and durability of the end portions of the teeth is secured. Besides embodying the advantageous features just recited, teeth of the shape and .type set forth may be conveniently out by a suitable machine which is adapted to move the cutting tool in a continuous sweeping stroke across the face of the gear.

Modifications in the structural details and arrangement and location of parts may be made without departing from the spirit and scope of my invention, and I desire that limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. A gear embodying a plurality of teeth adapted to mesh with similar teeth, each tooth having different finite radii of curvature at various portions thereof.

f gear.

2. A gear having a plurality .of teeth that aie adapted to mesh with similar teeth and are of continually varying curvature.

3. A gear having a plurality of overlapping teeth adapted to mesh with similar teeth and being of continually varying curi cal peripheral teeth of continually varyingA curvature, the maximum curvature being substantially in the middle portion of the 6. A ous teeth that are adapted to mesh with similar teeth and are of continually varying curvature.

7. A gear having a plurality of symmetrically curved peripheral teeth of compound curvature.

8. A gear having a plurality of continuous symmetrically curved teeth of compound curvature, having the maximum curvature substantially in the central plane of the frear. D n

9. A gear having a plurality of correspondingly disposed continuously curved teeth of compound curvature that are adapted to mesh with similar teeth the centers ot' curvature being on the same side of the tooth curve.

10. A gear havinga plurality of correspondingly disposed teeth of continually varying curvature, that are adapted to mesh with similar teeth, the ends of the teeth overlapping the central portions of the adjacent teeth.

11. A gear having a plurality of correspondingly disposed symmetrically curved teeth of compound curvature having the maximum curvature in the central plane of the gear.

12. A gear having a plurality of correspondmgly disposed continuous and symgear having a plurality of continu- Y metrically curved teeth of compound curvature, said teeth having'their maximum curvatures in substantiallyi the central plane of the gear and overlapping one another.

13. A gear having a plurality of correspondingly disposed teeth adapted to mesh with similar teeth, the said teeth having central portions of maximum curvature and symmetrically disposed end portions of materially less curvature, the teeth being so located that a line joining the extremities ot' the end portions of each tooth cuts the adjacent tooth.

. 14. A gear embodying a plurality of peripheral teeth, each of which has different nite radii of curvature at'various portions n testimony whereof, I have hereunto thereof, the centers of such curvature being subscribed lmy name this 27th day of June,

all on one side of the tooth curve. 913.

15. A gear having a plurality of perph- GEORGE M. EATN. 5 eral teeth of continually varying curvature,v Witnesses: v

the centers of such curvature being alleen H. D. JAMES,-

one side of the tooth curve. l B. B. HINEs.- 

